Mechanical Transformation Light Mix!

It's summer vacation in the third grade of elementary school. Hinagata Akari encounters a mysterious creature named Doc in her grandmother's storehouse and is granted the magic to fuse with dolls. When she uses this power to save her younger brother, Tango, she becomes an idol, a beautiful woman in a kimono, a mermaid, and even a supergirl... and her days become incredibly busy!?